Stop motion for knitting machines



Feb. 13, 1940. J. D. NORMANDEAU 2,190,521

STOP MOTION FOR KNITTING MACHINES 1958 2 Sheets Sheet 1 Filed June 23,

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STOP MOTION FOR KNITTING" MACHINES Filed June 23, 1938 2 Sheets-Sheet 2 ao FIEE. P E: 115.7 1- s ms 0 9 I I r V INVENTOR. w BYM ZI MQ Patented Feb. 13, 1940 UNITED STATES PATENT OFFICE' STOP MOTION FOR KNITTING MACHINES Joseph D. Normandeau, Nashua, H.

Application June 23, 1938, Serial No. 215,366

8 Claims. (01. 66-163) This invention relates to stop motions for knitting machines. It is particularly adapted for what are known as spring needle machines, although it can be adapted for latch needle machines. To be of any practical use, a stop motion for a knitting machine must be of such a character that if the tension on the thread is too great for any reason, such as the passing of a slub, or if the tension is too little, the stop motion will stop the machine. If the tension is too great or too small, within certain limits, there is a flaw in the fabric. any point, the stop motion should stop the machine before the broken end runs into the fabric and if a knot or slub ofgreater than a certain size is formed, the machine should be stopped before this gets into the fabric.

The mechanism must not be loaded up by lint, grease or oil to get it out of adjustment as it is very delicate and must be carefully adjusted; and while it is necessary that some parts, suchas the feeler fingers, should be exposed to air drafts, it should be so arranged that if the thread blows off from a finger, the machine will stop and prevent a press-off.

While a run, a flaw, a hole, or a place where the thread is too tight or too loose is objectionable and makes undesirable fabric, all the parts of .a stop motion must be so simple, so readily adjustable and so easily kept adjusted that the differences in the tensions for different threads and on different machines can quickly be regulated.

I believe I have combined devices in this stop motion in such a Way that the stop motion fills all of the above requirements and I believe all of the various devices co-operate.

I provide a balloon guide which is nearest the unwinding thread, a gravity feeler which will stop the machine by making suitable electrical contacts if the tension at that point is too low and another double action feeler which preferably is at the top and which will stop the machine through a double action nose device if the tension is too much or too little, as if the thread blows off the feeler. The desired tension is carefully 'and accurately adjusted between the high and low points and preferably this double action feeler is entirely enclosed, even the slots for the feeler arms being closed, so that the adjustment will not be accidently changed by dirt or lint. On the other hand, it can be easilyregulated from the outside.

In spring needle machines, I prefer to locate the bottom or gravity feeler so that the thread runs through it before going to the double action Besides this, if a break occurs at Y feeler, but on certain latch needle machines, I. prefer to locate it between the double action feeler and the needles.

I provide a balloon guide to stop slubs or knots or to hold them back so as to increase the tension 6 and cause the double action feelerto operate and I also include a gravity feeler, all associated with the double action feeler, whereby all kinds of thread and all kinds of tension, all kinds of speed and all other conditions can be met. A practical l0 device of this character must be almost 100% perfect and must be capable of adjustment to all varying conditions which may occur.

Fig, 1 is an-elevation showing thesupports for my feelers where they are arranged in a line.

Fig. 2 is a side elevation of Fig. 1. v

Fig. 2A is a top plan view showing an alternative circular arrangement of the feelers desirable on some types of machines.

Fig. 3 is a detail elevation, partly in section, 20 of the top feeler, shown in full lines in its normal position and in dotted lines in the position the parts assume when .there is a break in the thread orthe thread blows off.

Fig. 4 is a view similar to Fig. 3 but showing the 25 feeler finger pulled down in the position it assumes when there is toomuch tension on the thread.

Fig. 5 is a back elevationof the. top feeler' shown in Figs. 3 and 4 with the cover removed 30 and the parts intheir normal position.

Fig, 6 is a sectional view on the line 6--6 in Fig.

5 as viewed from the left.

Fig. 7 is a view similar to Fig. 6 of a modification of the top feeler. v

Fig. 8 is a view similar to Fig. 3 of another modification of the top feeler showing in full lines the position of the parts when there is too little tension and in dotted lines when there is too much tension. 0

Fig. 9 is a side elevation of the bottom feeler in the position when the thread is in normal position and Fig. 10 is a similar view showing the position of the parts when the thread breaks.

Fig. 11 is a plan view, partly in section, of the 45 bottom feeler and its contacts.

Fig. 12 is a detail elevation showing the thread and adjoining parts as from the left of .Fig. 9.

Fig. 13 is a diagrammatic view of the preferred type of wiring.

' In the drawings, D represents part of a knitting machine, 90 being a. guard through which the thread A goes to the needles and other mechanisms.

S is an electrical stopping device which,

through a rod 9I, stops the machine when either the top feeler T or the bottom feeler B closes a circuit through a suitable system of wiring W.

E is a frame comprising the legs 93, 93 which are connected by a suitable brace 94 and at the middle by a. plate 95. The thread A, as shown, is wound on a cone 96 and runs up through a balloon guide K which comprises an eye 91 carried directly above cone 93 by a rod 98 attached to the plate 95 and adjustable thereon by a set screw 99. This eye is of such size .that,while it permits smallknots and slubs to pass, if anything larger than desired attempts to pass through, it will hold back the thread A and operate the top feeler T.

This thread A passes from the balloon guide K through a bottom feeler B which includes a fixed loop guide I9 formed with loop 3I and a movable feeler arm I8 medially pivoted at 32 to plate 95 and having the feeler finger end 33 which projects through a feeler slot IT in plate 95 and is bent up in V shape, as shown, so that the thread A lifts it when it passes above the two members of loop 3| and under 33.

The legs 8| and 82 of loop 3i are fixed in such positions with'reference to eye 91 that when thread A passes over the bottom one 82 and under end 33, it holds 33 up and does not, when under normal tension, touch leg 8i. Preferably a curved screen I34 is so carried by arm I8 as to fill slot I! in all positions, thus keeping out dirt and lint.

If the thread becomes slack for lack of sufficient minimum tension, as when an end breaks, end 33 drops by gravity. The minimum or stopping tension is determined by the weight of end 33.

The back end of the arm I8 is bent up at 34 and is of less weight than the feeler finger end 33 so that when end 33 drops and 34 moves forward, it pushes against one end 35 of a movable contact arm M pivoted medially at 31 behind plate 95. Arm M is grounded and its other end 36 is in such a position that when the feeler finger end 33 drops, the inside end 34 moves end 35 of arm M and its other end 36, which carries the movable contact 38, against the light spring 39 so that contact 38 engages the insulated fixed contact 60 which is in the operating circuit W.

Supporting plate P is detachably attached to frame E in any suitable way, as by screws 3, 3, and has for each top feeler T two slots I and 2.

From each bottom feeler B, the thread goes up to a. top feeler T which includes a feeler arm 4 loosely pivoted at I4 on a shaft F carried inside plate P and cover C. This arm 4 extends at II out through a feeler slot I in supporting plate P to which, by shaft F, the feeler T is attached. At the outside, this part I I is bent down to form a concave contact finger I0, preferably of porcelain or other hard material. The inside end I2 of the arm 4 extends inside the plate P and, as shown, is threaded to carry an adjustable V counterweight I5.

Pin I6 also projects on the other carries at its tip 25 a movable contact 5 to engage the stationary contact 22, while its other end 21 is in such a position that when the feeler arm is'in the normal position, as shown by the full lines in Fig. 3, the spring 26 holds this movable contact 5 away from the stationary contact 22.

When, however, there is too little tension on the finger I0, counterweight I5 drops, as shown by the dotted lines in Fig. 3, causing the pin I6 to so move the end 21 and, therefore, end 25 and the movable contact 5 against spring 26 that the operating circuit is closed between contacts 5 and 2.2.

It is desirable that the contact finger I should be kept by the pull of the thread in a normal position and should be held there by a yieldable adjustable stop which will yield to extra tension. This, as shown, includes a spring arm H loosely pivoted on shaft F with one end I normally engaging the part 84 of pin I6 which extends through disk 83. One end of spring G, coiled around shaft F, tends to so press end I that if it were not for the other end 8 of arm H, which forms a stop arm, finger IIl would be constantly lifted. End 8 thus opposes spring G and keeps finger ID in the desired normal position. Such a spring arm with a suitable stop, or some other suitable stop, thus working against spring G, holds this spring arm H normally in a stationary position until or unless there is an extra pull by the thread on finger I0.

Spring G is coiled around shaft F and is attached to wheel L which extends out through and fills adjusting slot 2 and is held in adjusted position by means of a spring stop 9.

The adjusted pressure of spring G predetermines the maximum tension on thread A. If that tension goes beyond the maximum, as when a knot is caught in the balloon guide B, finger I0 is pulled down and ends I2 and 'I move up, thus turning disc 83 and causing contacts and 22 to engage.

The three-sided cover C is fastened to the plate and over the mechanisms by means of screws or bolts such as 30 but carries none of the operating parts.

In Fig. '7, I show another variation in which R represents a supporting plate with a suitable slot I5 and V is a cover. The contact arm N is the same as in the first described device.

The feeler arm 54 is similar to arm 4, being loosely pivoted on shaft 55 fixed inside plate R and has a tension adjustment wheel similar to L which is not shown. It has a feeler finger 56 outside and an adjustable counterweight I55 on its inside end 51, but instead of noses in the form of pins I6 and I3, it carries a rectangular cam 58, the edges of which serve as noses I5"! and I58 which cause the movable contact arm N to complete the circuit when the maximum or the minimum tension is reached. In the normal position, the contacts are kept out of engagement because the end 2'! rests against both noses I57 and I58, as it does against the noses or pins I3 and I6 in the other construction. I

I0 represents a spring arm, for the same purpose as arm H, loosely pivoted on shaft 55 and having one end I59 which is bent around and over the inside end 51 of feeler arm 54 and another end 14 which serves as a stop in such a way that it will strike plate R and thus hold arm "ID in the desired position against the pressure of spring 'II.

Spring II is coiled around shaft 55, one end being attached to arm 10 and the other end preferably attached to a wheel 12. similar to L as indicated in Fig. 7. No shield for the slot is shown in this construction.

In Fig. 8, I show a variation of the above arrangement. 0 represents a plate with suitable slots and'dI a cover and to this cover is attached a stationary insulated bracket 39 carrying contact 42 which is in the operating circuit W. 03 is a shaft located inside the cover and back to the plate and on this is a top feeler arm 40 which projects out through a slot and is formed as a finger 40, while the inside end 45 is weighted at 46.

Arm 40 is pivoted on the shaft 43 annd carries the two sprig metal arms or noses 4'5 and 48, each with a grounded contact I41, and IE0 which can engage the top or bottom of insulated contact 42 when the weight 40 causes the finger M of arm 40 to rise or when there is enough pull down on that finger M to overcome the resistance of the spring arm 49 actuated by the spring BI. This spring BI is preferably adjustable by a wheel 62 carried on the same shaft 03 as arm 09.

- Wheel 02 is similar to L and can be held in place by a stop spring B3. 64 is a stop which, as shown, is another end of spring arm 00 to prevent spring SI and arm 49 from pressing down inside end 45 of the feeler arm and, therefore, lifting the feeler finger M beyond a predetermined point.

Clearly, the arrangement of the top and bottom feelers could be, as shown in Fig. 2A, where there is a central supporting shaft 63 from which four arms such as 06, each carrying atop feeler 81, project. Under these arms 55 are arms '68, each carrying at an end a bottom feeler 69 over a cone 96. Such an arrangement is often desirable with certain types of circular knitting machines such, for instance, as shown in my pending application for United States Letters Patent, filed February 16, 1937, Serial No. 126,029.

Fig. 13 shows diagrammatically wiring which I find is convenient and practical.

I00 represents the ground connection for both the top feelers T and the bottom feelers B and their respective movable contacts 5 and 38, while the insulated wires IM and I02 extend from the fixed contacts 22 and 50. A current of perhaps four volts from a transformer I00 is preferably used for these contacts, while a current of twenty-four volts passes through the wire I00 through the solenoid S and back through the wire I01 when the twenty-four volt circuit is closed by a relay I09 in the four volt circuit. When the twenty-four volt circuit is closed by relay I09 through conductors MI and I01, solenoid S attracts a shipper or trigger arm 9| which controls the stopping devices for stopping the machine, whatever those devices may be, and at the same time arm 9|, which is mechanically connected to a circuit breaker I I0 breaks the four volt circuit through conductors I00, WI and I09 and the feeler contacts and keeps the four volt circuit open until the stopping devices are reset to start the machine.

I claim:

1. The combinationin a feeler device-for knitting machines of a supporting plate having two slots; and a protecting cover detachable there-' from; with a feeler arm medially pivoted to a shaft inside the plate and inside the cover with one end extending out through a curved movable screen which fills one slot and is then formed as a concave feeler finger and with the inside end carrying an adjustable counterweight to exert a predetermined minimum lifting pressure on said feeler finger; said shaft carried by the plate inside the cover; an adjusting wheel carried by the shaft and projecting from the plate through and filling the other slot; means to lock the wheel; a spring arm loosely pivoted on the shaft with an end which presses down the inside end of the feeler arm; a tension adjusting spring between and attached to the wheel and to the spring arm to cause it to press the inside of the feeler arm down; a stop to limit the downward movement of the spring arm caused by the pressure of the spring; a stationary contact carried by the plate and in circuit with electrical knitting frame stopping devices; a movable contact carried by a contact arm medially pivoted to the plate and normally held out of engagement with the stationary contact; and two noses carried by the feeler arm to move the movable contact so as to close the circuit through said stationary contact when the counterweight drops or when the stop is moved by the feeler arm against the spring arm to a predetermined point. I

2. The combination in a feeler device for knitting machines of asupporting plate having two slots; and a protecting cover detachable therefrom; with a-feeler arm medially pivoted to the plate with one end extending out through a curved mov able screen which fills one slot and is then formed as a concave feeler finger and with the inside end provided with means to exert a predetermined minimum lifting pressure on said feeler finger; a shaft carried by the plate; an adjusting wheel carried by'the shaft and projecting from the plate through and filling the other slot; means to lock the wheel; a. spring arm loosely pivoted 'on the shaft with an end which presses down the inside end of the feeler arm; a tension adjusting spring between and attached to the wheel and to the spring arm to cause it to press the inside of the feeler arm down; a stop to limit the downward movement of the spring arm caused by the pressure of the spring; a stationary contact carried by the plate and in circuit with electrical knitting frame stopping deout of engagement withthe stationary contact;

and two noses carried by the feeler arm to rock the contact arm and to cause the contacts to engage when the feeler finger moves to a predetermined point in either direction.

3. The combination in a stop motion for knitting machines; of electrical devices operable by a high voltage current to stop the machine; with devices operable by a low voltage circuit to close the circuit for said stopping devices; a top stationary contact and a bottom stationary contact, both in the low voltage circuit; a top feeler, including a medially pivoted single feeler arm with a feeler finger at one end which is concave and open at the top and over which the thread passes, a yieldable adjustable stop'to keep the other end of the feeler arm normally below a predetermined point until a predetermined maximum pressure is exerted by the thread and means to cause said other end of the feeler arm to drop when a predetermined minimum pressure is exor belowlthe minimum; a balloon guide extending down below a bottom feeler, including an eye positioned above the yarn package to control ballooming, for catching knots, and to operate the top feeler; and a bottom feeler positioned be tween the balloon guide eye and the top feeler, including a friction loop guide and a movable feeler arm whereby the yarn holds up the arm and holdsfa movable grounded contact attached to the arm normally out of engagement with the bottom stationary contact, whereby, if the thread breaks or the pressure drops below another minimum, the bottom feeler will close the circuit and stop the machine.

4. The combination in a stop motion for knitting machines; of electrical devices operable by a high voltage chrrent to stop the machine; with devices operable by a low voltage circuit to close the circuit for said stopping devices; a top stationary contact and a bottom stationary contact, both in the low voltage circuit; a top feeler, in-

cluding a medially pivoted single feeler arm with a feeler finger at one end which is concave and open at the top and over which the thread passes, a yieldable adjustable stop to keep the other end of the feeler arm normally below a predetermined point until a predetermined maximum pressure is exerted by the thread and means to cause said other end of the feeler arm to drop when a predetermined minimum pressure is exerted on the feeler finger, together with grounded attachments, whereby a movable contact will engage the stationary top contact when the' pressure on the feeler finger is above the maximum or below the minimum; and a bottom feeler positioned below the top feeler, including a friction loop guide and a movable feeler arm whereby the yarn holds up the arm and holds a movable ballooning, for catching knots, and to operate the grounded contact attached to the arm normally out oi! engagement with the bottom stationary contact, whereby, if the thread breaks or the pressure drops below another minimum, the bottom feeler will close the circuit and stop the ma chine.

5. The combination in a stop motion for knitting machines; of electrical devices-operable by a high voltage current to stop the machine; with devices operably by a low voltage circuit to close the circuit for said stopping devices; a top stationary contact in the low voltage circuit; a top feeler, including a medially pivoted single feeler arm with a feeler finger at one end which is open at the top and over which the thread passes, a yieldable adjustable stop to keep the other end of the feeler arm normally below a predetermined point until a predetermined maximum pressure is exerted by the thread and means to cause said other end of the feeler arm to drop when a predetermined minimum pressure is exerted on the feeler finger, together with grounded attachments, whereby a movable contact will engage the stationary top contact when the pressure on the feeler finger is above the maximum or below the minimum; a balloon guide extending down below a bottom feeler, including an eye positioned above the yarn package to control top feeler.

6. The combination in a stop motion for knitting machines; of electrical devices operable by a high voltage current to stop the machine; with devices operable by a low voltage circuit to close the circuit for said stopping devices; a top stationary contact in the low voltage circuit; a top feeler, including a medially pivoted single feeler arm with a feeler finger at one end which is open at the top and over which the thread passes, a yieldable adjustable stop to keep the other end of the feeler arm normally below a predetermined point until a predetermined maximum pressure is exerted by the thread and means to cause said other end of the feeler arm to drop when a predetermined minimum pressure is exerted on the feelerfinger, together with grounded attachments, whereby'a movable contact will engage the stationary top contact when the pressure on the feeler finger is above the maximum or below the minimum.

'7. The combination in a.stop motion for knitting machines; of electrical devices operable to stop the machine; with devices to close the circuit for said stopping devices; a stationary contact in the circuit; a feeler, including a medially pivoted single feeler arm with a feeler finger at one end which is open at the top and over which the thread passes, a yieldable adjustable stop to keepthe other end of the feeler arm normally below a predetermined point until a predetermined maximum pressure is exerted by the thread and means to cause said other end of the feeler arm to drop when a predetermined minimum pressure is exerted on the feeler finger together with grounded attachments, whereby a movable contact will engage the stationary contact when the pressure on the feeler finger is above the maximum or below the minimum.

8. The combination in a feeler device for knitting machines of a supporting plate having two slots; and a protecting cover detachable therefrom; with a feeler arm medially pivoted to a shaft inside the plate and inside the cover with one' end extending out through a curved movable screen which fills one slot and is then formed as a concave feeler finger and with the inside end carrying an adjustable counterweight to exert a predetermined minimum lifting pressure on said feeler finger; said shaft carried by the plate inside the cover; an adjusting wheel carried by the shaft and projecting from the plate through and filling the other slot; means to lock the wheel; a spring arm loosely pivoted on the shaft with an end which presses down the inside end of the feeler arm; a tension adjusting spring between and attached to the wheel and to the spring arm to cause it to press the inside of the feeler arm down; a stop to limit the downward movement of the spring arm caused by the pressure of the spring; a stationary contact in circuit with electrical knitting frame stopping devices; and two noses carried by the feeler arm to close the cir cuit through said stationary contact when the counterweight drops or when the stop is moved by the feeler arm against the spring arm to a predetermined point.

JOSEPH D. NORMANDEAU. 

